June 6 , 2000 -
The same technology that the city of Denver plans to use to make sure its workers in the field aren't goofing off has helped rescue lost cabbies and track down stolen cabs.

It's also ensured that drivers of Regional Transportation District buses, detoured by construction, didn't miss any riders on their routes.

Global Positioning System, or GPS, technology has been used in Denver for at least five or six years. It's used by transit authorities, trucking companies and parks and recreation agencies across the country. Versions of GPS receivers are used by hikers and in autos with vehicle navigation systems.

Created by the Department of Defense in the 1970s, the system uses 24 satellites orbiting the Earth. The satellites emit pulses that are detected by a receiver. Distances are measured by how much time it takes for the pulses to reach the receiver. Using more than one satellite, the crisscrossed signals pinpoint the location of the receiver.

In four years, GPS has nearly doubled the efficiency of Yellow Transportation company, which operates Yellow Cab in Denver and Boulder and the Super Shuttle airport ride service, said Michael Brown, director of technology.

"In 1996, we took 1.2 million calls; last year we took 2.3 million, with the same number of cabs," Brown said. Such efficiency is crucial in a city where 85-90 percent of requests for cabs are made on the telephone. The company operates about 440 vehicles.

Yellow Cab combines GPS with a computerized dispatching method called digital dispatch systems. With an old voice system, a good dispatcher could answer 200 calls an hour; their computerized method can answer 200 calls a minute, Brown said.

Brown said Yellow Transportation spent about $1 million on GPS and digital dispatch in 1996, and has spent an additional $600,000 for improvements since then.

Another main benefit of GPS is safety for the drivers, he said. About six months after GPS was operational, a cabbie picked up a fare who appeared to have a broken leg. He asked if the driver could stop at a convenience store, and if she would mind going inside to buy him a snack.

Wanting to oblige the passenger with the bum leg, she did. He then took off with her cab.

She used a pay phone to alert the dispatch center, which plugged the cab number into GPS. They were able to track the precise location of the stolen cab and police caught the thief 10 blocks from the convenience store, Brown said.

The system came in handy last Friday night for Yellow Cab driver Dick Richards. He had picked up an intoxicated passenger in LoDo. During the ride, the passenger said he had a gun and threatened to shoot Richards. Richards activated the emergency button and police were alerted. The man didn't have a weapon, but Richards feels somewhat safer with GPS in the cab.

"Overall, at least from a safety point of view, it has some distinct advantages," said Richards.

Richards said he understands the concerns that have been raised by Denver public works employees. But, he said, "There may be some privacy issues, but when we work for other people, we should expect to give up a little privacy. They have a right to know what's going on." The RTD has used GPS on its fleet of 900 buses and light-rail trains since 1995, said spokesman Scott Reed.

Reed said the system works very well for its purpose, which is mainly to make sure buses and trains are keeping to their schedule. Because the system records the travel times, they can verify customer complaints about whether a bus was running late.

Denver's plan to use GPS to monitor the whereabouts of city workers drew criticism from labor representatives and others concerned about a possible invasion of the workers' privacy. Private-sector employers don't face the same scrutiny when it comes to privacy issues.

Reed said RTD drivers were somewhat wary when the GPS system was first installed. "They were concerned about the Big Brother aspect at first," he said.

But the system allowed managers to make sure drivers were getting enough layovers and rest time on their routes as well, which they viewed as a positive.

And monitoring bus drivers wasn't the aim of the system in the first place.

Said Reed: "It's hard to wander off with a bus."

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